EFFECTS OF STIMULUS PRESENTATION ORDER DURING AUDITORY–VISUAL CONDITIONAL DISCRIMINATION TRAINING FOR CHILDREN WITH AUTISM SPECTRUM DISORDER JULIE E. CUBICCIOTTI,JASON C. VLADESCU AND KENNETH F. REEVE CALDWELL UNIVERSITY REGINA A. CARROLL UNIVERSITY OF NEBRASKA MEDICAL CENTER’S MUNROE-MEYER INSTITUTE LAUREN K. SCHNELL HUNTER COLLEGE Children with autism spectrum disorder are typically taught conditional discriminations using a match-to-sample arrangement. Consideration should be given to the temporal order in which antecedent stimuli (the sample and comparison stimuli) are presented during match-to-sample trials, as various arrangements have been used in the extant literature. The purpose of the cur- rent study was to compare the effects of four stimulus presentation orders on the acquisition of auditory–visual conditional discriminations. The study included participants from a clinically relevant population (three children with autism spectrum disorder), employed clinically relevant teaching procedures, and included two presentation formats not included in previous compari- son evaluations (simultaneous and sample-first with re-presentation conditions). Results were found to be learner-specific; that is, a different stimulus presentation format was most efficient for each participant. We provide suggestions to evaluate stimulus control topographies and enhance experimental control in match-to-sample arrangements. Key words: autism spectrum disorder, conditional discriminations, discrete trial training, instructional efficiency, matching to sample, stimulus control When developing the procedural arrange- ment of match-to-sample (MTS) trials, consid- eration should be given to the temporal order in which antecedent stimuli (i.e., the compari- son and sample stimuli) are presented. The sample stimulus could be presented prior to (i.e., sample-first arrangement) or following (i.e., comparison-first arrangement) the presen- tation of the comparison stimuli. Additionally, the sample and comparison stimuli could be presented simultaneously (i.e., simultaneous arrangement). The effects of temporal order of stimulus presentations during MTS are particu- larly applicable to consumers with autism spec- trum disorder, considering the frequency with which conditional discriminations are estab- lished using MTS paradigms for this popula- tion. Consumers with autism spectrum disorder, as opposed to their peers of typical development, often require explicit teaching procedures to facilitate differential responding to environmental stimuli (Grow & LeBlanc, 2013). One difficulty that necessitates and complicates instruction is that faulty stimulus control (from the perspective of the teacher) may develop with consumers with autism spec- trum disorder (i.e., weak stimulus control and/or inappropriate stimulus control, such as stimulus overselectivity, stimulus bias, or posi- tion bias; Pilgrim, 2015). At present, it is This article is based on a thesis submitted by the first author, under the supervision of the second author, at Caldwell University in partial fulfillment for the require- ments of the Master of Arts in Applied Behavior Analysis. Address correspondence to Jason C. Vladescu, Department of Applied Behavior Analysis, Caldwell University, 120 Bloomfield Avenue, Caldwell, NJ 07006. E-mail: jvladescu@caldwell.edu doi: 10.1002/jaba.530 JOURNAL OF APPLIED BEHAVIOR ANALYSIS 2018, 9999, 1–16 NUMBER 9999 () © 2018 Society for the Experimental Analysis of Behavior 1